淮南地区荷斯坦奶牛乳用特征的线性评定

随机选择安徽淮南乳品公司的荷斯坦奶牛493头(1～11胎)进行奶牛乳用特征性状即楞角性、尻宽、尻角度、后肢侧视、蹄角度的线性评定。结果表明:淮南地区荷斯坦奶牛乳用特征性状的表现中等偏好,楞角性、尻宽、尻角度、后肢侧视、蹄角度的评定等级分别是佳、优、中、中、良;优秀率是20%,中等率为40%。同时,楞角性、尻宽、蹄角度的线性评分随胎次变化而变化的幅度很小,且未表现出一定的规律;而后肢侧视、尻角度的线性评分在1～5胎内随胎次的升高而有明显的升高,并且前者的变异幅度大于后者。     

奶牛乳用特征性状对305天产奶量的主成分分析

笔者在安徽淮南益益乳品公司第一奶牛场开展试验,随机抽取荷斯坦奶牛165头,其中1胎~3胎各55头,进行乳用特征性状[即楞角性(x_1)、尻宽(x_2)、尻角度(x_3)、后肢侧视(x_4)、蹄角度(x_5)]对305d产奶量的主成分分析。结果表明:(1)x_1~x_5线性分的平均值分别为26.95、32.00、27.13、28.40和23.73分。(2)主成分F1~F4的贡献率分别为29.10%、22.47%、18.65%和17.18%,累积贡献率达87.39%。(3)主成分F1~F4的表达式分别为F1=-0.4776x_1+0.4777x_2-0.3885x_3+0.1317x_4+0.6127x_5;F2=0.4612x_1+0.4224x_2+0.0536x_3-0.7454x_4+0.2244x_5;F3=-0.4052x_1-0.1144x_2+0.8294x_3-0.1557x_4+0.3326x_5;F4=0.3441x_1+0.6259x_2+0.3974x_3+0.5690x_4-0.0901x_5。(4)对主成分F1~F4贡献最大的性状分别是蹄角度、后肢侧视、尻角度和尻宽。     

奶牛隐性乳房炎对产奶量、乳成分和奶中物理指标的影响

为了研究奶牛隐性乳房炎对产奶量、乳常规成分、乳密度和冰点的影响 ,对哈尔滨市及周边地区的 2 89头中国荷斯坦奶牛进行了调查 ,对其中 5 1头患隐性乳房炎奶牛和 2 5头健康奶牛的乳常规成分、乳密度和乳冰点进行了测定。结果表明 :调查地区的奶牛隐性乳房炎阳性率为 75 %。隐性乳房炎导致产奶量下降 ,平均减少 2 .75kg/d ;乳脂肪含量显著低于健康奶牛 (P <0 .0 5 ) ;总酪蛋白和乳糖含量极显著低于健康奶牛 (P <0 .0 1) ;而乳干物质、总蛋白质、非脂固形物的含量及乳密度、乳冰点与健康奶牛无显著差异 (P >0 .0 5 )。     

中牟县某奶牛场奶牛乳房炎的发生规律分析

为了掌握奶牛乳房炎的发生规律,通过对河南省中牟县某奶牛场随机抽样500头奶牛的乳房炎检测,获得临床型和隐性型乳房炎的一系列相关数据,并对奶牛乳房炎的发生与胎次、月份、泌乳时期、分娩头数、乳区、日产奶量等之间的关系进行统计分析。结果显示:各胎次之间奶牛乳房炎发生存在极显著差异(P0.01),胎次与总阳性率、临床阳性率、隐性阳性率之间的相关系数分别为0.826 8(P0.01)、0.928 8(P0.01)、0.663 8(P0.05);各月份之间奶牛乳房炎发生率差异显著(P0.05);而临床型与隐性型间差异极显著(P0.01),二者之间的相关系数为0.992 6(P0.01);随着泌乳时期延长奶牛乳房炎发生率有增高的趋势,且二者间具有极显著的相关性(P0.01);各月份的分娩头数与临床型、隐性型乳房炎间的相关系数分别为0.858 6(P0.01)、0.862 6(P0.01);4个乳区乳房炎发生率差异不显著(P0.05),前后乳区间、左右乳区间也差异不显著(P0.05);日产奶量4个水平之间阳性率差异不显著(P0.05),而日产奶量与总阳性率、临床阳性率、隐性阳性率间的相关系数分别为-0.961 9、-0.910 4、-0.946 5,三者均极显著(P0.01)。本研究结果可为有效防治奶牛乳房炎疾病提供参考。     

如何选购良种奶牛

1看体型奶牛整个身躯要高大,舒展,体高在1.4～1.5米之间,胸宽、体深,背腰平直,腹大而不下垂,腰部结合紧密。三个三角形明显,即从前面、侧面、背部三个方位观察均呈三角形。2看尻部奶牛尻部应长、平、宽。腰角高于坐骨结节端4厘米左右,两坐骨结节间宽18厘米以上。3看肢蹄后肢骨骼宽、扁平、细致、灵活,耐久性好,结实有力。后肢侧看成镰刀状弯曲(飞节呈145度角),后肢后视平行。蹄角度65度左右,蹄踵深度2.5厘米以上。四个蹄子蹄瓣完好无损,内外蹄紧密对称。4看乳房乳房发育充分,呈浴盆状,前伸后延。质地柔软细致,富有弹性。四乳区分布均匀,乳中…     

奶牛外貌性状对305d产奶量的多元回归分析

为了进行奶牛外貌性状对305 d产奶量的多元回归分析,试验选择荷斯坦奶牛180头,其中1~3胎各60头,测定其体高(X_1)、胸宽(X_2)、体深(X_3)、尻角度(X_4)、尻宽(X_5)、后肢侧视(X_6)、蹄角度(X_7)外貌性状,对奶牛305 d产奶量进行多元回归分析。结果表明:尻宽、蹄角度、体深与305 d产奶量的相关系数分别为0.306 5,0.260 7,0.246 8;多元回归方程为Y=2761.00-19.33X_1+12.30X_2+41.46X_3-17.66X_4+55.61X_5+3.51X_6+43.25X_7,达极显著水平(P0.01),但自变量X_1、X_2、X_3、X_4、X_6的偏回归系数未达到显著水平(P0.05);最优回归方程Y=2635.83+39.55X_3+46.26X_5+41.43X_7,回归方程及自变量的偏回归系数均达显著水平(P0.05)。说明奶牛外貌性状对305 d产奶量的最优回归方程的建立能够为提高奶牛生产性能提供思路。     

奶牛乳头评分与隐性乳房炎发生率的相关性研究

研究奶牛乳头评分与奶牛隐性乳房炎发病率之间的相关性,通过改善乳头评分来降低隐性乳房炎的发病率。试验随机抽取泌乳奶牛100头,采用电导率法测定隐性乳房炎发生率,并进行相关性分析。结果显示,奶牛隐性乳房炎总阳性率为19.0%,奶牛各乳区(左前、右前、左后、右后)隐性乳房炎的发病率分别为20%、26%、19%、11%,前乳区的发病率高于后乳区,但差异不显著(P0.05);隐性乳房炎发生率与乳头评分的相关系数为0.91,呈显著正相关(P0.05)。结果表明,隐性乳房炎发生率与乳头评分显著相关。     

荷斯坦奶牛体型线性评定与其产奶量、乳脂率及乳蛋白的相关性分析

通过对扬州大学实验农牧场的212头产奶牛进行了奶牛体型线性评定,并采集其奶样,测出其乳脂率和乳蛋白率,统计产奶量并校正为305d的产奶量。对体型线性评定、乳蛋白率、乳脂率和产奶量进行相关性分析,结果表明:产奶量与棱角度、体高和体深呈正相关,其中与棱角度相关极显著(P<0.01),与体高和体深相关显著(P<0.05),与后乳房深、后乳房宽、悬韧带、后肢侧视、尻宽、蹄角度、胸宽、乳头长和乳头位置间均负相关显著;乳脂率与悬韧带、体高间呈极显著正相关,与胸宽呈极显著负相关;乳蛋白与乳头位置、乳头长、体深呈正相关,其中与乳头长、体深相关极显著,与乳头位置相关显著,与后肢侧视、胸宽呈显著负相关。     

不同血统含量、世代及胎次奶牛体型线性评分研究

为了选出优秀体型奶牛群体,提高全群产奶量,试验选取不同血统含量、不同世代、不同胎次的286头奶牛开展体型线性评分研究。结果显示:纯种荷斯坦牛体型总评分、乳房评分、体躯结构评分(P0.05)以及乳用特征评分高于或显著高于低代杂种,而低代杂种肢蹄评分、尻部评分高于纯种;2世代奶牛在肢蹄评分、体躯结构评分、乳用特征评分方面显著高于0世代(P0.05),0世代尻部评分显著高于2世代(P0.05);2胎次奶牛总评分、乳房评分、肢蹄评分以及体躯结构评分显著高于1胎次(P0.05),2胎次以后总评分呈下降趋势。提示:应加强纯种荷斯坦牛的肢蹄和尻部结构选育工作,从而减少肢蹄病和产科疾病的发生,使得奶牛群体高产健康长寿。     

荷斯坦奶牛不同胎次外貌性状间的相关性分析

笔者在安徽淮南益益乳品公司第一奶牛场牛群中,随机抽取荷斯坦奶牛165头,其中1胎~3胎各55头,进行不同胎次奶牛外貌性状体高(x1)、胸宽(x2)、体深(x3)、尻角度(x4)、尻宽(x5)、后肢侧视(x6)、蹄角度(x7)间的相关分析。结果表明,第1胎次,体高、体深与其他性状的相关系数均为正值;第2胎次,尻角度与其他性状的相关系数均为负值;其余各性状间在各胎次相关性质有正有负。就各性状的相关性而言,在胎次间未表现出较明显的变化趋势,时正时负。就各性状的相关程度而言,总体表现出相关系数绝对值随胎次升高而降低的趋势,即相关的密切程度减小。     

Genetic Parameters of Foot and Leg Traits in Future AI Bulls: II. Correlation to Body Conformation Traits in Daughters

The aim of this investigation was to establish genetic correlations between foot and leg traits in future potential AI bulls and body conformation traits in their daughters. Data consisted of records of 2394, 5002 and 1098 bulls of the breeds Danish Red, Danish Friesian and Jersey, respectively, which were correlated according to breed with 11846, 62875 and 10954 daughters sand their contemporaries, respectively. The bull traits included hoof measurements, horn characteristics and claw disease frequencies recorded at hoof trimming, while the data for the dairy cows contained the scores for rear leg side view, rear leg rear view, bone structure, quality of hocks and foot angle. The correlations between the claw diseases or horn characteristics on one side and the daughters' conformation on the other side were either negligible or inconclusive, while those between the bull's hoof measurements and the two conformation traits bone structure and hock quality were of statistical significance for all three breeds. Moreover, the stance of the rear leg showed a significant relationship to claw measurements in Danish Red and Jersey cattle. Small feet in bulls were correlated with a favourable expression of feet and legs in daughters. An improvement in foot and leg conformation traits in dairy cattle is possible by including claw measurements in the selection of future AI bulls.     

西门塔尔牛14项线性体型评分的正态分布检验

１４项线性体型性状引入到包括蒙贝利亚和弗列克维两个类群７０头成年母牛的西门塔尔牛群。体高，强壮度，乳用性，尻宽，前乳房附着，后乳房宽度，乳头位置和乳房静脉８个性状附合正态分布。而后腿侧观，尻宽，后乳房高度，乳房支撑和乳房匀度的评分具有偏崎，乳房深度偏崎十分明显。１３项评分性状是呈陡峰现象，只有乳房静脉一项不是；呈现陡峰现象的原因可能是分值取自于数个评分员的平均值所致。     

Genetic evaluation of dairy cattle for conformation traits using random regression models

Random regression models were applied to eight conformation traits (i.e. stature, rump angle, thurl width, rear leg set, rear udder width, rear udder height, udder depth, and fore udder attachment) of Holstein cows from the northeastern United States. Covariates for fixed and random regressions included age and age‐squared for six of the traits, and two additional covariates were included for rear udder width and rear udder height. Other effects in the model were herd—year‐classifier and months in milk. Fixed covariates were nested within year of birth of the cow. Variance components were estimated using Bayesian theory and Gibbs sampling procedure. Estimated breeding values from the random regression models were compared to two single trait models. The first model utilized only the first classification record of the cow in first lactation, and the second model utilized all classifications of the cow in a simple repeatability model. Additive genetic merit for conformation traits changed with the age of the animal. Some traits were affected by age more than others. The single trait, single record model and the simple repeatability model were not appropriate in predicting breeding values at mature ages for rear udder width and rear udder height.     

奶牛9分制体型线性评分数据的正态性分析

[目的]检验中国荷斯坦牛体型线性鉴定9分制评分法评分后的数据是否服从正态分布。[方法]根据971头荷斯坦母牛23个体型性状转化为9分制评分后的数据,我们分别用标准差区间的频率检验、矩法正态性检验、正态Q－Q概率图检验、直方图模拟正态分布检验等4种方法进行分析检验。[结果]前段、乳房深度、尻角度、胸宽、后肢侧视等性状明显服从正态分布;体躯大小、体深、腰强度、骨质地等性状不服从正态分布。[结论]23个体型线性性状经过9分制转化后的数据多数仍然近似服从正态分布。     

Genetic background of claw disorders in the course of lactation and their relationships with type traits

Random regression threshold animal models were applied to binary longitudinal claw disorder data for studying genetic parameters of all claw disorders (ACD), as well as to claw disorders divided into different categories: non‐purulent claw disorders (NPCD), purulent claw disorders (PCD), dermatitis digitalis (DD), sole ulcer (SU), phlegmona (PH), laminitis (LAM) and interdigital hyperplasia (IH) in the course of lactation. Claw disorder data were obtained from 26 651 Holstein cows kept in 15 large‐scale contract herds in the region of Thuringia over a period of 5 years from 2007 to 2012. If a cow had one or more entries of the same disorder, for example, sole ulcer, within an interval of 30 days, she was scored with a ‘1’, and otherwise, she received a score of ‘0’ for healthy. Heritabilities for the same disorder were relatively stable between DIM 50 and DIM 300, but they tended to increase in early and late lactation. Highest heritabilities in the range from 0.20 to 0.34 were estimated for IH, and lowest heritabilities were realized for LAM (~ 0.05). Genetic correlations for same traits between different DIMs were high for adjacent test days, but close to zero for distant test days. The relationship between the sire EBVs for claw disorders and official sire EBVs for the type traits ‘foot angle’ was slightly antagonistic with correlation coefficients in the range from 0.05 (DD) to 0.33 (PH). Correlations between lactation EBVs for hock quality, rear leg rear view and the feet and leg index with EBVs for claw disorders were slightly favourable and ranged between ?0.01 (rear leg rear view correlated with SU) and ?0.43 (hock quality correlated with PH). Regarding daily EBVs for claw disorders, the strongest correlation coefficient was of value ?0.46 (LAM early in lactation correlated with the feet and leg index). Genetic parameters from the random regression model were verified by applying a single‐trait repeatability model. Correlation coefficients between lactation EBVs from the random regression model and lactation EBVs from the repeatability model for the same claw disorder were close to 1. Correlations were lower between EBVs from single test days and lactation EBVs from the repeatability models, with a minimal value of 0.58 for PCD measured at day 20.     

探讨微卫星作为地方山羊品种生长性状的遗传标记

采用微卫星技术及最小二乘拟合线性模型，利用崂山奶山羊、济宁青山羊、鲁北白山羊和莱芜黑山羊4个地方山羊品种中的10个多态性微卫星基因座，分析了微卫星基因座及其等位基因对山羊生长性状的关联效应。结果表明：与品种、性别和年龄等因子比较，标记因子对山羊体重和体尺性状的影响较小，但发现BM6404、BM1818、BM812和BM6444基因座对体重有显著影响（P〈0．05或P〈0．01），BM6404、BM1818、BMS12484、MAF70基因座对主要体尺性状有显著影响（P〈0．05或P〈O．01）。BM6404基因座的等位基因130可能对山羊的胸围、体高、尻宽均有正效应；120对胸围有较强的负效应，而对体高、尻长则有较强的正效应；168对尻长、尻宽均表现为负效应。MAF70基因座的等位基因142对体长有正效应，178对体长有负效应。BMS1248基因座的等位基因128对管围有正效应。     

荷斯坦奶牛牛嘴宽度影响因素分析及遗传参数估计

【目的】探究中国荷斯坦奶牛牛嘴宽度的群体规律,并估计其遗传参数。【方法】2021年7月至2021年8月分别在2个规模化奶牛场测定了628头泌乳期荷斯坦奶牛的牛嘴宽度及臀高、体高、体斜长和胸围等体尺性状,同时利用体斜长和胸围估计试验牛体重。利用SPSS 26.0软件分析了牧场、月龄和泌乳阶段等因素对牛嘴宽度的影响,以及牛嘴宽度与各体尺性状之间的相关关系;基于DMU软件采用单性状动物模型估计了牛嘴宽度的方差组分及遗传力。【结果】荷斯坦奶牛牛嘴宽度的群体平均值为17.28 cm,变异系数为5%,变异相对较小;牧场和月龄对牛嘴宽度均有极显著影响（P<0.01）,泌乳阶段对牛嘴宽度有显著影响（P<0.05）,牛嘴宽度随母牛月龄的增加呈逐渐增加的趋势,泌乳初期牛嘴宽度显著小于其他泌乳阶段（P<0.05）;牛嘴宽度与各体尺性状之间存在极显著正相关（P<0.01）;荷斯坦奶牛牛嘴宽度的遗传力估计值为0.28,为中高遗传力性状。【结论】牧场和月龄对奶牛牛嘴宽度影响极显著,泌乳阶段对奶牛牛嘴宽度影响显著,牛嘴宽度与臀高呈较弱相关。荷斯坦奶牛牛嘴宽度是一个具有中高遗传力的体尺性状。     

The Relationship between Linear Type Traits and Fertility Traits in High‐yielding Dairy Goats

Reproductive data collected from 13 medium‐size goat farms in central Mexico (582 goats), were used to investigate if linear type traits influenced reproductive performance of high‐yielding dairy goats. Data were analysed using multiple stepwise forward logistic regressions. Goats with the higher scores for strength were 1.43 times more likely (p < 0.05) to have larger litters (1.49 vs 1.39) than goats with lower strength. Goats approaching level rump angles were 1.68 times more likely (p < 0.01) to have larger litters, compared with goats with extremely sloped rump angles (1.48 vs 1.37). Goats with rear legs nearly straight (posty) in hock tended (p < 0.08) to presented larger litters than goats with rear legs slightly angled (sickled) in hock (1.49 vs 1.38). Less pronounced rump angle was favourable associated (p < 0.05) with litter weight (4.88 vs 4.53 kg) compared with goats with low pin bones. Goats with poorer udder texture were 1.42 more likely (p < 0.05) to have heavier litters than goats with good udder texture. Goats with faulty mammary system tended (p < 0.07) to have heavier litters than goats with good mammary system. Increasing udder height was associated (p < 0.05) with increasing number of services per conception. Goats with good fore udder attachment and non‐refined heads were at reduced risk (p < 0.05) for stillbirths. Goats with stronger median ligament were 65% less likely (p < 0.05) to lose their foetuses than those with looser udder support. Our findings indicate that a greater litter size and litter weight is expected in goats as rump angle becomes less sloped. This study showed that a relationship exists between strength of goats and litter size, and that some traits linked to high milk yield were antagonist to some reproductive traits.     

奶牛乳房性状与产奶量及排乳性能的关系

选择胎次相同,泌乳月份相近的经产荷斯坦牛197头,分别测定其后乳房宽度,后乳房深度,后乳房高度,乳房纵沟深,乳头直径,乳头长度等6个高遗传力性状,并与排乳性能及产奶量的相关性进行研究.结果表明:奶牛乳房纵沟深,乳头直径,乳头长度等6个高遗传力性状,并与排乳性能及产奶量的相关性进行研究.结果表明:奶牛乳房纵沟深、后乳房宽度、乳头长、乳头直径与排乳速度有极显著正相关(P＜0.01),后乳房高度与排乳速度呈现中等正相关(P＜0.05),平均排乳时间与后乳房宽度呈现显著正相关(P＜0.05);日产乳量与乳头长度呈中等负相关(P＜0.05),与乳房纵沟深、乳头直径呈显著正相关(P＜0.05),305 d产乳量与乳房纵沟深、后乳房宽度呈极显著强正相关(P＜0.01),与乳头直径呈显著正相关(P＞0.05),与乳头长度有极显著负相关(P＜0.01).